Hammer with detachable head



April 1964 A. CITROEN HAMMER WITH DETACHABLE HEAD l/al Filed Nov. 27, 1962 INVENTOR ARMAND CITROEN A ORNE Y$ United States Patent 3,129,737 HAMMER WITH DETACHABLE HEAD Armand Citroen, 96 Boulevard Maurice Barres, N euiliy-snr-Seine, France Filed Nov. 27, 1262, Ser. No. 240,216 Claims priority, application France Dec. 7, 1961 6 Claims. (6!. 145-29) This invention relates generally to hand tools and more particularly to an improved hammer having its hammer head quickly and easily detachable from its flexible handle while being securely mountable thereon.

Existing types of hammers are generally constructed with the head more or less permanently attached to the handle. Thus should either part become broken or worn, the entire unit must be discarded. Other hammer constructions utilizing detachable heads frequently lack structural rigidity or present difiicult disassembly problems.

A [further problem concerns the construction of the handle. Handles made of metal or wood or any other inelastic substance tend to transmit shock vibrations to the users hand. Furthermore, where the hammer is used in metal working, as with automotive sheets or panels, harsh and irritating noise conditions are created in the work area.

It is therefore an object of this invention to provide a hammer with detachable head wherein the handle and the hammer head are individual and separate entitieswhich can be rigidly assembled together, disassembled into component parts and reassembled in various combinations.

Another object of this invention is to provide a hammer with detachable head which is quick and easy to assemble and disassemble.

A further object of this invention is to provide a hammer with detachable head which, when fully assembled, is an integrated rigid hand tool that will not accidentally come apart under the stress of hammering.

A still further object of this invention is to provide a hammer with a flexible elastic handle, preferably having a co-axial passageway in the gripping portion of the handle to absorb sound and shock vibrations transmitted by the hammer head.

Other objects and advantages of this invention will become apparent from a study of the accompanying drawings and the descriptive matter in which is illustrated and described several preferred embodiments of this invention.

In the drawings:

FIG. 1 is a view in perspective partly cut away of the hammer with detachable head;

FIG. 2 is a view in perspective partly cut away of another species of hammer with detachable head; and

FIG. 3 is a view in perspective partly cut away of a third species of hammer with detachable head.

Reference is now directed to the drawings wherein an illustrated embodiment of the hammer with detachable head is fully shown in FIG. 1. The hammer is provided with a handle 10, preferably composed of a molded plastic or hard rubber material. Plastic is preferred because of its elasticity, toughness, and ability to dampen sound and shock waves. The handle can be molded with or without a hollow recess in the gripping portion as shown in FIG. 1. Such a recess increases the wave dampening effect.

An anchor post 12, preferably of a strong metal or alloy such as steel is embedded in the upper end of handle and extends upwardly therefrom. The lower portion of anchor post 12 has a narrow neck 16 and a wider conic nose 18 shaped to resist forces tending to wrench anchor post 12 from its seat within plastic handle 10. The shaping of conic nose 18 can obviously differ from that shown in FIG. 1, but should have a form that can be solidly ice embedded in the plastic handle 10. Anchor post 12 preferably has a co-axial passageway therein which is open at its top end and is internally threaded. It should be understood that an alternate construction of anchor post 12 could have a solid post with external threads thereon instead of a passageway and internal threads.

A hammer head 20 is provided with a passageway extending completely therethrough from upper surface 22 to lower surface 24. This passageway is of the same internal configuration as the external configuration of the upper end of anchor post 12 and is dimensioned so that hammer head 20 can he slipped over anchor post 12 with a minimum of play between the two members resulting. The striking faces 26 and 28 of hammer head 20 can be of any shape or design. This fulfills one of the purposes of the invention to allow various types of hammer heads to be employed with the same handle.

A retaining bolt 30 is threadably inserted in anchor post 12 to tightly secure hammer head 20 to handle lfi. Retaining bolt 30 preferably has a bolt head 31 with an angled underside 32 for fiush mounting in upper surface 22 of hammer head 2% (the passageway therein being countersunk). Retaining bolt 30 can alternatively be internally threaded if anchor post 12 is externally threaded. An additional means of insuring that retaining bolt 3% does not come loose during hammer use is to coat the passageway of anchor post 12 with a small amount of a latex solution. This solution will firmly grip retaining bolt 30 in anchor post 12, but still permit detachment of hammer head 20 by means of a screwdriver.

A finger or pin 34 is vertically positioned in recesses formed in the upper end of handle It and the lower surface 24 of hammer head Zil. Finger 34 alternatively can be molded integral with hammer head 20 or with handle 16 or, as shown in FIG. 1,freely positioned in the aligned recesses. Finger 34 primarily serves to prevent rotary movement of hammer head 26 about anchor post 12 and also tends to resist reaction forces opposite the direction of the hammer blows.

FIG. 2 illustrates another species of the described invention. Handle 10 has a shape similar to the handle configuration shown in FIG. 1 except that two shoulders 36 and 38 are molded in the upper end of the handle which mate and interact with correspondingly shaped grooves 40 and 42 formed in lower surface 24 of a hammer head 20. Other minor differences appearing in FIG. 2 with reference to FIG. 1 are a larger conic nose 18 of anchor post 12 and a rounded bolt head 31 which protrudes above upper surface 22 rather than being countersunk therein. These minor differences point out the many possibilities for slight design changes which are within the scope of this invention. The primary differentiation between the species of FIG. 1 and that of FIG. 2 lies in the means at the upper end of handle 10 for preventing the rotation of hammer head 20 about anchor post 12.

FIG. 3 illustrates a third species of the described invention. Here anchor post 12 is in the form of a hollow metal cylinder open at both ends. Anchor post 12 is internally threaded and is firmly mounted about protuberance 44 of handle 10 by having the handle formed inside of anchor post 12 and having shoulders 36 and 38 formed to tightly abut the lower periphery of anchor post 12. Shoulders 36 and 38 also interact with grooves 40 and 42 to prevent rotation of hammer head 24 about anchor post 12. Retaining bolt 30 has a large bolt head 31 which retains hammer head 20 on handle 10.

It can be clearly seen that this species differs from the species of FIG. 2 solely in the configuration of anchor post 12 and its manner of attachment to handle 10. In FIG. 3, the anchor post is open at both ends and handle 10 is attached thereto by being formed within the anchor a posts threaded passageway. In FIG. 2, the anchor post is closed at its lower end and conic nose 1.8 is embedded in plastic handle 10. All other elements of the two species are similar.

Operation The hammer is assembled by sliding hammer head 2!) over anchor post 12, aligning grooves 4-0 and 42 over shoulders 36 and 33 (in the species of FIGS. 2 and 3) or aligning the recess in lower surface 24 over finger 34 (in the species of FIG. 1), and securely fastening the assembled elements together by tightly screwing retaining bolt 3% into anchor post 12. The optional use of a latex solution with retaining bolt 3'3 is recommended in situations where frequent detaching of hammer head 29 is not anticipated or where the hammer is to be used with extreme force or will encounter twisting stresses.

The disassembly of the hammer is accomplished by simply unscrewing retaining bolt 30 with a screwdriver and removing hammer head 29 from anchor post 12. Even when the latex solution has been employed during assembly, firm pressure on the screwdriver will unseat retaining bolt 30, permitting removal of the hammer head.

Whereas the invention has been described by reference to three preferred embodiments thereof, it will be understood that numerous changes and modifications may be made therein without departing from the scope and spirit of the invention.

Having thus described my invention, I claim:

1. A hammer with detachable head comprising; a handle having upper and lower ends, said handle being of resilient composition and having walls forming a co-axial cavity in the lower end thereof, said cavity being open at its lower end; an anchor post embedded in the upper end of said handle and extending therefrom; a hammer head having a passageway therethrough dimensioned and arranged to receive said anchor post, said hammer head mounted on said handle over said anchor post; means at the upper end of said handle for preventing the rotation of said hammer about said anchor post; and means for fastening said hammer head to said handle, said fastening means engaging said anchor post and removably fixed thereto.

2. A hammer with detachable head according to claim 1 and further characterized by; said anchor post having an internally threaded co-axial passageway open at the upper end thereof for threadably receiving said fastening means.

3. A hammer with detachable head according to claim 1 and further characterized by; said anchor post having a coating of a latex solution whereby said fastening means is tightly gripped therein.

4. A hammer with detachable head comprising; a resilient handle having upper and lower ends, said handle having a co-axial cavity open at the lower end thereof; an anchor post embedded in the upper end of said handle and extending therefrom; a hammer head having a recess in the bottom surface thereof and a passageway therethrough dimensioned and arranged to receive said anchor post, said hammer head mounted on said handle over said anchor post; a pin mounted in the upper end of said handle and retained in said hammer head recess to prebent rotation of said hammer head about said anchor post; and means for fastening said hammer head to said handle, said fastening means engaging said anchor post and removably fixed thereto.

5. A hammer with detachable head comprising; a plastic handle having upper and lower ends and shoulders at the upper end thereof, said handle having a co-axial cavity open at the lower end thereof; an anchor post embedded in the upper end of said handle and extending therefrom; a hammer head having grooves in the bottom surface thereof and a passageway therethrough dimensioned and arranged to receive said anchor post, said hammer head mounted on said handle over said anchor post with said handle shoulders engaging said hammer head grooves; and means for fastening said hammer head to said handle, said fastening means engaging said anchor post and removably fixed thereto whereby rotation of said hammer head about said anchor post is prevented.

6. A hammer with detachable head comprising: a resilient handle having shoulders at the upper end thereof and walls forming a co-axial cavity in the lower end thereof open at its lower end; an anchor post formed in the upper end of said handle and extending therefrom, said anchor post having an internally threaded co-axial passageway open at its upper end thereof; a hammer head having grooves in the bottom surface thereof and the passageway therethrough dimensioned and arranged to receive said anchor post, said hammer head mounted on said handle over said post with said handle shoulders engaging said hammer head grooves to prevent rotation of said hammer head about said anchor post; and means for fastening said hammer head to said handle, said fastening means engaging said anchor post and removably fixed thereto.

References Cited in the file of this patent UNITED STATES PATENTS 698,436 Bolster Apr. 29, 1902 1,550,282 Rennerfelt Aug. 18, 1925 1,581,647 Layton Apr. 20, 1926 2,983,296 Lay May 9, 1961 

1. A HAMMER WITH DETACHABLE HEAD COMPRISING; A HANDLE HAVING UPPER AND LOWER ENDS, SAID HANDLE BEING OF RESILIENT COMPOSITION AND HAVING WALLS FORMING A CO-AXIAL CAVITY IN THE LOWER END THEREOF, SAID CAVITY BEING OPEN AT ITS LOWER END; AN ANCHOR POST EMBEDDED IN THE UPPER END OF SAID HANDLE AND EXTENDING THEREFROM; A HAMMER HEAD HAVING A PASSAGEWAY THERETHROUGH DIMENSIONED AND ARRANGED TO RECEIVE SAID ANCHOR POST, SAID HAMMER HEAD 